1. Technical Field
The present invention relates to position sensing, and more particularly to a system, device and method for sub-nanometer resolution position sensing which employs magneto-resistance.
2. Description of the Related Art
Position sensing with sub-nanometer resolution and high bandwidth in moving structures like piezo-scanners, flexure stages and Micro Electro Mechanical Systems (MEMS) based micro-scanners is important for closed-loop controlled operation to ensure positioning accuracy at very high speeds. Such moving stages are employed in scanning probe microscopes, nano-lithography tools, nanoscale data storage devices and experimental (probe-based) nano-fabrication tools.
Currently available position sensors based on optics, capacitors and inductive coils (for example, linear variable displacement transducers (LVDTs)), although accurate and fast, do not scale down (with respect to the dimension of the sensor) to micro-scales for use in micro-structures or in large-scale point-wise position sensing of macro-structures. Thermo-electric and piezo-resistive position sensors, on the other hand, easily scale down to micro-scale, but suffer from low bandwidth.